1. Field of the Invention
The present invention generally relates to air intake manifolds for internal combustion engines. In particular, the present invention is directed to an assembly and method for controlling an air intake runner of an air intake manifold in a naturally aspirated gas engine.
2. Description of the Related Art
It is generally known in the art of internal combustion engines that the length of the air intake runners between an intake air plenum and the engine cylinders impacts the power or torque output over a range of engine speeds. For example, long runners are preferred to obtain high torque output at low engine speeds, i.e., low revolutions per minute (RPMs). Conversely, short runners help provide high torque output at high engine speeds. It is also generally known that torque output reduces quickly at elevated RPM levels when only long runners are utilized. Also, the use of short runners at reduced RPM levels does not provide high torque.
Short/long runner control systems are known in the art for switching the short air intake runners between open and closed modes depending on the speed of the engine. Known systems are generally fabricated from a single material such as aluminum or plastic and require intensive machining or tooling to both fabricate and install in an intake manifold. Existing systems often have a reduced structural integrity due to their one-material construction. Finally, existing systems are often rigid and are not easy to adjust for varying operating conditions.